As the use of a multimedia service using a portable electronic device has increased, an amount of information which must be processed and displayed in the portable electronic device has also increased. Accordingly, there is a growing interest in a portable electronic device having a touch screen which may improve space utilization and increase a size of a display unit thereof.
The touch screen is an input and output device for inputting and displaying information. Accordingly, when the touch screen is installed in the electronic device, the electronic device may increase a display size by removing a separate input device such as a keypad.
As services which must be processed in the portable electronic device to satisfy various needs of a user is increased, it is a major issue to design a user interface for allowing the user to easily access the various services. In addition, because the portable electronic device includes a display size of a limited size due to portability, it is more necessary to provide a user interface for allowing the user to easily access the various services. For example, although the portable electronic device provides various contents to satisfy various needs of the user, there may be a problem in that the portable electronic device displays small contents due to a limited display size or displays only some of the contents. Accordingly, there is a need to provide a user interface of the portable electronic device for controlling functions such as zooming-in/out of contents, documents, or images displayed on a display unit of the portable electronic device.
As described above, when the touch screen is installed in the portable electronic device, because the portable electronic device does not have a separate input device such as a keypad, the portable electronic device operates different from an electronic device having its input device installed separately. Therefore, there is a need to provide an improved user interface for providing convenience of the user according to the touch screen in the portable electronic device having the touch screen. For example, there is a need to provide an improved user interface for zooming in/out a screen using the touch screen in the portable electronic device having the touch screen.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.